// jshint ignore: start
/* eslint-disable */

/*
 Copyright 2011 notmasteryet

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

// - The JPEG specification can be found in the ITU CCITT Recommendation T.81
//   (www.w3.org/Graphics/JPEG/itu-t81.pdf)
// - The JFIF specification can be found in the JPEG File Interchange Format
//   (www.w3.org/Graphics/JPEG/jfif3.pdf)
// - The Adobe Application-Specific JPEG markers in the Supporting the DCT Filters
//   in PostScript Level 2, Technical Note #5116
//   (partners.adobe.com/public/developer/en/ps/sdk/5116.DCT_Filter.pdf)

var ColorSpace = { Unkown: 0, Grayscale: 1, AdobeRGB: 2, RGB: 3, CYMK: 4 };
var dctZigZag = new Int32Array([
  0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, 18, 11, 4, 5, 12, 19, 26, 33, 40,
  48, 41, 34, 27, 20, 13, 6, 7, 14, 21, 28, 35, 42, 49, 56, 57, 50, 43, 36, 29,
  22, 15, 23, 30, 37, 44, 51, 58, 59, 52, 45, 38, 31, 39, 46, 53, 60, 61, 54,
  47, 55, 62, 63,
]);

var dctCos1 = 4017; // cos(pi/16)
var dctSin1 = 799; // sin(pi/16)
var dctCos3 = 3406; // cos(3*pi/16)
var dctSin3 = 2276; // sin(3*pi/16)
var dctCos6 = 1567; // cos(6*pi/16)
var dctSin6 = 3784; // sin(6*pi/16)
var dctSqrt2 = 5793; // sqrt(2)
var dctSqrt1d2 = 2896; // sqrt(2) / 2

function buildHuffmanTable(codeLengths, values) {
  var k = 0,
    code = [],
    i,
    j,
    length = 16;
  while (length > 0 && !codeLengths[length - 1]) length--;
  code.push({ children: [], index: 0 });
  var p = code[0],
    q;
  for (i = 0; i < length; i++) {
    for (j = 0; j < codeLengths[i]; j++) {
      p = code.pop();
      p.children[p.index] = values[k];
      while (p.index > 0) {
        p = code.pop();
      }
      p.index++;
      code.push(p);
      while (code.length <= i) {
        code.push((q = { children: [], index: 0 }));
        p.children[p.index] = q.children;
        p = q;
      }
      k++;
    }
    if (i + 1 < length) {
      // p here points to last code
      code.push((q = { children: [], index: 0 }));
      p.children[p.index] = q.children;
      p = q;
    }
  }
  return code[0].children;
}

function getBlockBufferOffset(component, row, col) {
  return 64 * ((component.blocksPerLine + 1) * row + col);
}

function decodeScan(
  data,
  offset,
  frame,
  components,
  resetInterval,
  spectralStart,
  spectralEnd,
  successivePrev,
  successive
) {
  var precision = frame.precision;
  var samplesPerLine = frame.samplesPerLine;
  var scanLines = frame.scanLines;
  var mcusPerLine = frame.mcusPerLine;
  var progressive = frame.progressive;
  var maxH = frame.maxH,
    maxV = frame.maxV;

  var startOffset = offset,
    bitsData = 0,
    bitsCount = 0;

  function readBit() {
    if (bitsCount > 0) {
      bitsCount--;
      return (bitsData >> bitsCount) & 1;
    }
    bitsData = data[offset++];
    if (bitsData == 0xff) {
      var nextByte = data[offset++];
      if (nextByte) {
        throw 'unexpected marker: ' + ((bitsData << 8) | nextByte).toString(16);
      }
      // unstuff 0
    }
    bitsCount = 7;
    return bitsData >>> 7;
  }

  function decodeHuffman(tree) {
    var node = tree;
    var bit;
    while ((bit = readBit()) !== null) {
      node = node[bit];
      if (typeof node === 'number') return node;
      if (typeof node !== 'object') throw 'invalid huffman sequence';
    }
    return null;
  }

  function receive(length) {
    var n = 0;
    while (length > 0) {
      var bit = readBit();
      if (bit === null) return;
      n = (n << 1) | bit;
      length--;
    }
    return n;
  }

  function receiveAndExtend(length) {
    var n = receive(length);
    if (n >= 1 << (length - 1)) return n;
    return n + (-1 << length) + 1;
  }

  function decodeBaseline(component, offset) {
    var t = decodeHuffman(component.huffmanTableDC);
    var diff = t === 0 ? 0 : receiveAndExtend(t);
    component.blockData[offset] = component.pred += diff;
    var k = 1;
    while (k < 64) {
      var rs = decodeHuffman(component.huffmanTableAC);
      var s = rs & 15,
        r = rs >> 4;
      if (s === 0) {
        if (r < 15) break;
        k += 16;
        continue;
      }
      k += r;
      var z = dctZigZag[k];
      component.blockData[offset + z] = receiveAndExtend(s);
      k++;
    }
  }

  function decodeDCFirst(component, offset) {
    var t = decodeHuffman(component.huffmanTableDC);
    var diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
    component.blockData[offset] = component.pred += diff;
  }

  function decodeDCSuccessive(component, offset) {
    component.blockData[offset] |= readBit() << successive;
  }

  var eobrun = 0;
  function decodeACFirst(component, offset) {
    if (eobrun > 0) {
      eobrun--;
      return;
    }
    var k = spectralStart,
      e = spectralEnd;
    while (k <= e) {
      var rs = decodeHuffman(component.huffmanTableAC);
      var s = rs & 15,
        r = rs >> 4;
      if (s === 0) {
        if (r < 15) {
          eobrun = receive(r) + (1 << r) - 1;
          break;
        }
        k += 16;
        continue;
      }
      k += r;
      var z = dctZigZag[k];
      component.blockData[offset + z] = receiveAndExtend(s) * (1 << successive);
      k++;
    }
  }

  var successiveACState = 0,
    successiveACNextValue;
  function decodeACSuccessive(component, offset) {
    var k = spectralStart,
      e = spectralEnd,
      r = 0;
    while (k <= e) {
      var z = dctZigZag[k];
      switch (successiveACState) {
        case 0: // initial state
          var rs = decodeHuffman(component.huffmanTableAC);
          var s = rs & 15;
          r = rs >> 4;
          if (s === 0) {
            if (r < 15) {
              eobrun = receive(r) + (1 << r);
              successiveACState = 4;
            } else {
              r = 16;
              successiveACState = 1;
            }
          } else {
            if (s !== 1) throw 'invalid ACn encoding';
            successiveACNextValue = receiveAndExtend(s);
            successiveACState = r ? 2 : 3;
          }
          continue;
        case 1: // skipping r zero items
        case 2:
          if (component.blockData[offset + z]) {
            component.blockData[offset + z] += readBit() << successive;
          } else {
            r--;
            if (r === 0) successiveACState = successiveACState == 2 ? 3 : 0;
          }
          break;
        case 3: // set value for a zero item
          if (component.blockData[offset + z]) {
            component.blockData[offset + z] += readBit() << successive;
          } else {
            component.blockData[offset + z] =
              successiveACNextValue << successive;
            successiveACState = 0;
          }
          break;
        case 4: // eob
          if (component.blockData[offset + z]) {
            component.blockData[offset + z] += readBit() << successive;
          }
          break;
      }
      k++;
    }
    if (successiveACState === 4) {
      eobrun--;
      if (eobrun === 0) successiveACState = 0;
    }
  }

  function decodeMcu(component, decode, mcu, row, col) {
    var mcuRow = (mcu / mcusPerLine) | 0;
    var mcuCol = mcu % mcusPerLine;
    var blockRow = mcuRow * component.v + row;
    var blockCol = mcuCol * component.h + col;
    var offset = getBlockBufferOffset(component, blockRow, blockCol);
    decode(component, offset);
  }

  function decodeBlock(component, decode, mcu) {
    var blockRow = (mcu / component.blocksPerLine) | 0;
    var blockCol = mcu % component.blocksPerLine;
    var offset = getBlockBufferOffset(component, blockRow, blockCol);
    decode(component, offset);
  }

  var componentsLength = components.length;
  var component, i, j, k, n;
  var decodeFn;
  if (progressive) {
    if (spectralStart === 0)
      decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive;
    else decodeFn = successivePrev === 0 ? decodeACFirst : decodeACSuccessive;
  } else {
    decodeFn = decodeBaseline;
  }

  var mcu = 0,
    marker;
  var mcuExpected;
  if (componentsLength == 1) {
    mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn;
  } else {
    mcuExpected = mcusPerLine * frame.mcusPerColumn;
  }
  if (!resetInterval) {
    resetInterval = mcuExpected;
  }

  var h, v;
  while (mcu < mcuExpected) {
    // reset interval stuff
    for (i = 0; i < componentsLength; i++) {
      components[i].pred = 0;
    }
    eobrun = 0;

    if (componentsLength == 1) {
      component = components[0];
      for (n = 0; n < resetInterval; n++) {
        decodeBlock(component, decodeFn, mcu);
        mcu++;
      }
    } else {
      for (n = 0; n < resetInterval; n++) {
        for (i = 0; i < componentsLength; i++) {
          component = components[i];
          h = component.h;
          v = component.v;
          for (j = 0; j < v; j++) {
            for (k = 0; k < h; k++) {
              decodeMcu(component, decodeFn, mcu, j, k);
            }
          }
        }
        mcu++;
      }
    }

    // find marker
    bitsCount = 0;
    marker = (data[offset] << 8) | data[offset + 1];
    if (marker <= 0xff00) {
      throw 'marker was not found';
    }

    if (marker >= 0xffd0 && marker <= 0xffd7) {
      // RSTx
      offset += 2;
    } else {
      break;
    }
  }

  return offset - startOffset;
}

// A port of poppler's IDCT method which in turn is taken from:
//   Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz,
//   "Practical Fast 1-D DCT Algorithms with 11 Multiplications",
//   IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989,
//   988-991.
function quantizeAndInverse(component, blockBufferOffset, p) {
  var qt = component.quantizationTable;
  var v0, v1, v2, v3, v4, v5, v6, v7, t;
  var i;

  // dequant
  for (i = 0; i < 64; i++) {
    p[i] = component.blockData[blockBufferOffset + i] * qt[i];
  }

  // inverse DCT on rows
  for (i = 0; i < 8; ++i) {
    var row = 8 * i;

    // check for all-zero AC coefficients
    if (
      p[1 + row] === 0 &&
      p[2 + row] === 0 &&
      p[3 + row] === 0 &&
      p[4 + row] === 0 &&
      p[5 + row] === 0 &&
      p[6 + row] === 0 &&
      p[7 + row] === 0
    ) {
      t = (dctSqrt2 * p[0 + row] + 512) >> 10;
      p[0 + row] = t;
      p[1 + row] = t;
      p[2 + row] = t;
      p[3 + row] = t;
      p[4 + row] = t;
      p[5 + row] = t;
      p[6 + row] = t;
      p[7 + row] = t;
      continue;
    }

    // stage 4
    v0 = (dctSqrt2 * p[0 + row] + 128) >> 8;
    v1 = (dctSqrt2 * p[4 + row] + 128) >> 8;
    v2 = p[2 + row];
    v3 = p[6 + row];
    v4 = (dctSqrt1d2 * (p[1 + row] - p[7 + row]) + 128) >> 8;
    v7 = (dctSqrt1d2 * (p[1 + row] + p[7 + row]) + 128) >> 8;
    v5 = p[3 + row] << 4;
    v6 = p[5 + row] << 4;

    // stage 3
    t = (v0 - v1 + 1) >> 1;
    v0 = (v0 + v1 + 1) >> 1;
    v1 = t;
    t = (v2 * dctSin6 + v3 * dctCos6 + 128) >> 8;
    v2 = (v2 * dctCos6 - v3 * dctSin6 + 128) >> 8;
    v3 = t;
    t = (v4 - v6 + 1) >> 1;
    v4 = (v4 + v6 + 1) >> 1;
    v6 = t;
    t = (v7 + v5 + 1) >> 1;
    v5 = (v7 - v5 + 1) >> 1;
    v7 = t;

    // stage 2
    t = (v0 - v3 + 1) >> 1;
    v0 = (v0 + v3 + 1) >> 1;
    v3 = t;
    t = (v1 - v2 + 1) >> 1;
    v1 = (v1 + v2 + 1) >> 1;
    v2 = t;
    t = (v4 * dctSin3 + v7 * dctCos3 + 2048) >> 12;
    v4 = (v4 * dctCos3 - v7 * dctSin3 + 2048) >> 12;
    v7 = t;
    t = (v5 * dctSin1 + v6 * dctCos1 + 2048) >> 12;
    v5 = (v5 * dctCos1 - v6 * dctSin1 + 2048) >> 12;
    v6 = t;

    // stage 1
    p[0 + row] = v0 + v7;
    p[7 + row] = v0 - v7;
    p[1 + row] = v1 + v6;
    p[6 + row] = v1 - v6;
    p[2 + row] = v2 + v5;
    p[5 + row] = v2 - v5;
    p[3 + row] = v3 + v4;
    p[4 + row] = v3 - v4;
  }

  // inverse DCT on columns
  for (i = 0; i < 8; ++i) {
    var col = i;

    // check for all-zero AC coefficients
    if (
      p[1 * 8 + col] === 0 &&
      p[2 * 8 + col] === 0 &&
      p[3 * 8 + col] === 0 &&
      p[4 * 8 + col] === 0 &&
      p[5 * 8 + col] === 0 &&
      p[6 * 8 + col] === 0 &&
      p[7 * 8 + col] === 0
    ) {
      t = (dctSqrt2 * p[i + 0] + 8192) >> 14;
      p[0 * 8 + col] = t;
      p[1 * 8 + col] = t;
      p[2 * 8 + col] = t;
      p[3 * 8 + col] = t;
      p[4 * 8 + col] = t;
      p[5 * 8 + col] = t;
      p[6 * 8 + col] = t;
      p[7 * 8 + col] = t;
      continue;
    }

    // stage 4
    v0 = (dctSqrt2 * p[0 * 8 + col] + 2048) >> 12;
    v1 = (dctSqrt2 * p[4 * 8 + col] + 2048) >> 12;
    v2 = p[2 * 8 + col];
    v3 = p[6 * 8 + col];
    v4 = (dctSqrt1d2 * (p[1 * 8 + col] - p[7 * 8 + col]) + 2048) >> 12;
    v7 = (dctSqrt1d2 * (p[1 * 8 + col] + p[7 * 8 + col]) + 2048) >> 12;
    v5 = p[3 * 8 + col];
    v6 = p[5 * 8 + col];

    // stage 3
    t = (v0 - v1 + 1) >> 1;
    v0 = (v0 + v1 + 1) >> 1;
    v1 = t;
    t = (v2 * dctSin6 + v3 * dctCos6 + 2048) >> 12;
    v2 = (v2 * dctCos6 - v3 * dctSin6 + 2048) >> 12;
    v3 = t;
    t = (v4 - v6 + 1) >> 1;
    v4 = (v4 + v6 + 1) >> 1;
    v6 = t;
    t = (v7 + v5 + 1) >> 1;
    v5 = (v7 - v5 + 1) >> 1;
    v7 = t;

    // stage 2
    t = (v0 - v3 + 1) >> 1;
    v0 = (v0 + v3 + 1) >> 1;
    v3 = t;
    t = (v1 - v2 + 1) >> 1;
    v1 = (v1 + v2 + 1) >> 1;
    v2 = t;
    t = (v4 * dctSin3 + v7 * dctCos3 + 2048) >> 12;
    v4 = (v4 * dctCos3 - v7 * dctSin3 + 2048) >> 12;
    v7 = t;
    t = (v5 * dctSin1 + v6 * dctCos1 + 2048) >> 12;
    v5 = (v5 * dctCos1 - v6 * dctSin1 + 2048) >> 12;
    v6 = t;

    // stage 1
    p[0 * 8 + col] = v0 + v7;
    p[7 * 8 + col] = v0 - v7;
    p[1 * 8 + col] = v1 + v6;
    p[6 * 8 + col] = v1 - v6;
    p[2 * 8 + col] = v2 + v5;
    p[5 * 8 + col] = v2 - v5;
    p[3 * 8 + col] = v3 + v4;
    p[4 * 8 + col] = v3 - v4;
  }

  // convert to 8-bit integers
  for (i = 0; i < 64; ++i) {
    var index = blockBufferOffset + i;
    var q = p[i];
    q =
      q <= -2056 / component.bitConversion
        ? 0
        : q >= 2024 / component.bitConversion
          ? 255 / component.bitConversion
          : (q + 2056 / component.bitConversion) >> 4;
    component.blockData[index] = q;
  }
}

function buildComponentData(frame, component) {
  var lines = [];
  var blocksPerLine = component.blocksPerLine;
  var blocksPerColumn = component.blocksPerColumn;
  var samplesPerLine = blocksPerLine << 3;
  var computationBuffer = new Int32Array(64);

  var i,
    j,
    ll = 0;
  for (var blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
    for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
      var offset = getBlockBufferOffset(component, blockRow, blockCol);
      quantizeAndInverse(component, offset, computationBuffer);
    }
  }
  return component.blockData;
}

function clampToUint8(a) {
  return a <= 0 ? 0 : a >= 255 ? 255 : a | 0;
}

class JpegImage {
  constructor() {}

  // setting up all the prototype functions
  // javascript new version of setting up prototype functions
  load(path) {
    var handleData = function (data) {
      this.parse(data);
      if (this.onload) this.onload();
    }.bind(this);

    if (path.indexOf('data:') > -1) {
      var offset = path.indexOf('base64,') + 7;
      var data = atob(path.substring(offset));
      var arr = new Uint8Array(data.length);
      for (var i = data.length - 1; i >= 0; i--) {
        arr[i] = data.charCodeAt(i);
      }
      handleData(data);
    } else {
      var xhr = new XMLHttpRequest();
      xhr.open('GET', path, true);
      xhr.responseType = 'arraybuffer';
      xhr.onload = function () {
        // TODO catch parse error
        var data = new Uint8Array(xhr.response);
        handleData(data);
      }.bind(this);
      xhr.send(null);
    }
  }

  parse(data) {
    function readUint16() {
      var value = (data[offset] << 8) | data[offset + 1];
      offset += 2;
      return value;
    }

    function readDataBlock() {
      var length = readUint16();
      var array = data.subarray(offset, offset + length - 2);
      offset += array.length;
      return array;
    }

    function prepareComponents(frame) {
      var mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
      var mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
      for (var i = 0; i < frame.components.length; i++) {
        component = frame.components[i];
        var blocksPerLine = Math.ceil(
          (Math.ceil(frame.samplesPerLine / 8) * component.h) / frame.maxH
        );
        var blocksPerColumn = Math.ceil(
          (Math.ceil(frame.scanLines / 8) * component.v) / frame.maxV
        );
        var blocksPerLineForMcu = mcusPerLine * component.h;
        var blocksPerColumnForMcu = mcusPerColumn * component.v;

        var blocksBufferSize =
          64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
        component.blockData = new Int16Array(blocksBufferSize);
        component.blocksPerLine = blocksPerLine;
        component.blocksPerColumn = blocksPerColumn;
      }
      frame.mcusPerLine = mcusPerLine;
      frame.mcusPerColumn = mcusPerColumn;
    }

    var offset = 0,
      length = data.length;
    var jfif = null;
    var adobe = null;
    var pixels = null;
    var frame, resetInterval;
    var quantizationTables = [];
    var huffmanTablesAC = [],
      huffmanTablesDC = [];
    var fileMarker = readUint16();
    if (fileMarker != 0xffd8) {
      // SOI (Start of Image)
      throw 'SOI not found';
    }

    fileMarker = readUint16();
    while (fileMarker != 0xffd9) {
      // EOI (End of image)
      var i, j, l;
      switch (fileMarker) {
        case 0xffe0: // APP0 (Application Specific)
        case 0xffe1: // APP1
        case 0xffe2: // APP2
        case 0xffe3: // APP3
        case 0xffe4: // APP4
        case 0xffe5: // APP5
        case 0xffe6: // APP6
        case 0xffe7: // APP7
        case 0xffe8: // APP8
        case 0xffe9: // APP9
        case 0xffea: // APP10
        case 0xffeb: // APP11
        case 0xffec: // APP12
        case 0xffed: // APP13
        case 0xffee: // APP14
        case 0xffef: // APP15
        case 0xfffe: // COM (Comment)
          var appData = readDataBlock();

          if (fileMarker === 0xffe0) {
            if (
              appData[0] === 0x4a &&
              appData[1] === 0x46 &&
              appData[2] === 0x49 &&
              appData[3] === 0x46 &&
              appData[4] === 0
            ) {
              // 'JFIF\x00'
              jfif = {
                version: { major: appData[5], minor: appData[6] },
                densityUnits: appData[7],
                xDensity: (appData[8] << 8) | appData[9],
                yDensity: (appData[10] << 8) | appData[11],
                thumbWidth: appData[12],
                thumbHeight: appData[13],
                thumbData: appData.subarray(
                  14,
                  14 + 3 * appData[12] * appData[13]
                ),
              };
            }
          }
          // TODO APP1 - Exif
          if (fileMarker === 0xffee) {
            if (
              appData[0] === 0x41 &&
              appData[1] === 0x64 &&
              appData[2] === 0x6f &&
              appData[3] === 0x62 &&
              appData[4] === 0x65 &&
              appData[5] === 0
            ) {
              // 'Adobe\x00'
              adobe = {
                version: appData[6],
                flags0: (appData[7] << 8) | appData[8],
                flags1: (appData[9] << 8) | appData[10],
                transformCode: appData[11],
              };
            }
          }
          break;

        case 0xffdb: // DQT (Define Quantization Tables)
          var quantizationTablesLength = readUint16();
          var quantizationTablesEnd = quantizationTablesLength + offset - 2;
          while (offset < quantizationTablesEnd) {
            var quantizationTableSpec = data[offset++];
            var tableData = new Int32Array(64);
            if (quantizationTableSpec >> 4 === 0) {
              // 8 bit values
              for (j = 0; j < 64; j++) {
                var z = dctZigZag[j];
                tableData[z] = data[offset++];
              }
            } else if (quantizationTableSpec >> 4 === 1) {
              //16 bit
              for (j = 0; j < 64; j++) {
                var zz = dctZigZag[j];
                tableData[zz] = readUint16();
              }
            } else throw 'DQT: invalid table spec';
            quantizationTables[quantizationTableSpec & 15] = tableData;
          }
          break;

        case 0xffc0: // SOF0 (Start of Frame, Baseline DCT)
        case 0xffc1: // SOF1 (Start of Frame, Extended DCT)
        case 0xffc2: // SOF2 (Start of Frame, Progressive DCT)
          if (frame) {
            throw 'Only single frame JPEGs supported';
          }
          readUint16(); // skip data length
          frame = {};
          frame.extended = fileMarker === 0xffc1;
          frame.progressive = fileMarker === 0xffc2;
          frame.precision = data[offset++];
          frame.scanLines = readUint16();
          frame.samplesPerLine = readUint16();
          frame.components = [];
          frame.componentIds = {};
          var componentsCount = data[offset++],
            componentId;
          var maxH = 0,
            maxV = 0;
          for (i = 0; i < componentsCount; i++) {
            componentId = data[offset];
            var h = data[offset + 1] >> 4;
            var v = data[offset + 1] & 15;
            if (maxH < h) maxH = h;
            if (maxV < v) maxV = v;
            var qId = data[offset + 2];
            l = frame.components.push({
              h: h,
              v: v,
              quantizationTable: quantizationTables[qId],
              quantizationTableId: qId,
              bitConversion: 255 / ((1 << frame.precision) - 1),
            });
            frame.componentIds[componentId] = l - 1;
            offset += 3;
          }
          frame.maxH = maxH;
          frame.maxV = maxV;
          prepareComponents(frame);
          break;

        case 0xffc4: // DHT (Define Huffman Tables)
          var huffmanLength = readUint16();
          for (i = 2; i < huffmanLength; ) {
            var huffmanTableSpec = data[offset++];
            var codeLengths = new Uint8Array(16);
            var codeLengthSum = 0;
            for (j = 0; j < 16; j++, offset++)
              codeLengthSum += codeLengths[j] = data[offset];
            var huffmanValues = new Uint8Array(codeLengthSum);
            for (j = 0; j < codeLengthSum; j++, offset++)
              huffmanValues[j] = data[offset];
            i += 17 + codeLengthSum;

            (huffmanTableSpec >> 4 === 0 ? huffmanTablesDC : huffmanTablesAC)[
              huffmanTableSpec & 15
            ] = buildHuffmanTable(codeLengths, huffmanValues);
          }
          break;

        case 0xffdd: // DRI (Define Restart Interval)
          readUint16(); // skip data length
          resetInterval = readUint16();
          break;

        case 0xffda: // SOS (Start of Scan)
          var scanLength = readUint16();
          var selectorsCount = data[offset++];
          var components = [],
            component;
          for (i = 0; i < selectorsCount; i++) {
            var componentIndex = frame.componentIds[data[offset++]];
            component = frame.components[componentIndex];
            var tableSpec = data[offset++];
            component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4];
            component.huffmanTableAC = huffmanTablesAC[tableSpec & 15];
            components.push(component);
          }
          var spectralStart = data[offset++];
          var spectralEnd = data[offset++];
          var successiveApproximation = data[offset++];
          var processed = decodeScan(
            data,
            offset,
            frame,
            components,
            resetInterval,
            spectralStart,
            spectralEnd,
            successiveApproximation >> 4,
            successiveApproximation & 15
          );
          offset += processed;
          break;
        case 0xffff: // Fill bytes
          if (data[offset] !== 0xff) {
            // Avoid skipping a valid marker.
            offset--;
          }
          break;
        default:
          if (
            data[offset - 3] == 0xff &&
            data[offset - 2] >= 0xc0 &&
            data[offset - 2] <= 0xfe
          ) {
            // could be incorrect encoding -- last 0xFF byte of the previous
            // block was eaten by the encoder
            offset -= 3;
            break;
          }
          throw 'unknown JPEG marker ' + fileMarker.toString(16);
      }
      fileMarker = readUint16();
    }

    this.width = frame.samplesPerLine;
    this.height = frame.scanLines;
    this.jfif = jfif;
    this.adobe = adobe;
    this.components = [];
    switch (frame.components.length) {
      case 1:
        this.colorspace = ColorSpace.Grayscale;
        break;
      case 3:
        if (this.adobe) this.colorspace = ColorSpace.AdobeRGB;
        else this.colorspace = ColorSpace.RGB;
        break;
      case 4:
        this.colorspace = ColorSpace.CYMK;
        break;
      default:
        this.colorspace = ColorSpace.Unknown;
    }
    for (var i = 0; i < frame.components.length; i++) {
      var component = frame.components[i];
      if (
        !component.quantizationTable &&
        component.quantizationTableId !== null
      )
        component.quantizationTable =
          quantizationTables[component.quantizationTableId];
      this.components.push({
        output: buildComponentData(frame, component),
        scaleX: component.h / frame.maxH,
        scaleY: component.v / frame.maxV,
        blocksPerLine: component.blocksPerLine,
        blocksPerColumn: component.blocksPerColumn,
        bitConversion: component.bitConversion,
      });
    }
  }

  getData16(width, height) {
    if (this.components.length !== 1) throw 'Unsupported color mode';
    var scaleX = this.width / width,
      scaleY = this.height / height;

    var component, componentScaleX, componentScaleY;
    var x, y, i;
    var offset = 0;
    var numComponents = this.components.length;
    var dataLength = width * height * numComponents;
    var data = new Uint16Array(dataLength);
    var componentLine;

    // lineData is reused for all components. Assume first component is
    // the biggest
    var lineData = new Uint16Array(
      (this.components[0].blocksPerLine << 3) *
        this.components[0].blocksPerColumn *
        8
    );

    // First construct image data ...
    for (i = 0; i < numComponents; i++) {
      component = this.components[i];
      var blocksPerLine = component.blocksPerLine;
      var blocksPerColumn = component.blocksPerColumn;
      var samplesPerLine = blocksPerLine << 3;

      var j,
        k,
        ll = 0;
      var lineOffset = 0;
      for (var blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
        var scanLine = blockRow << 3;
        for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
          var bufferOffset = getBlockBufferOffset(
            component,
            blockRow,
            blockCol
          );
          var offset = 0,
            sample = blockCol << 3;
          for (j = 0; j < 8; j++) {
            var lineOffset = (scanLine + j) * samplesPerLine;
            for (k = 0; k < 8; k++) {
              lineData[lineOffset + sample + k] =
                component.output[bufferOffset + offset++];
            }
          }
        }
      }

      componentScaleX = component.scaleX * scaleX;
      componentScaleY = component.scaleY * scaleY;
      offset = i;

      var cx, cy;
      var index;
      for (y = 0; y < height; y++) {
        for (x = 0; x < width; x++) {
          cy = 0 | (y * componentScaleY);
          cx = 0 | (x * componentScaleX);
          index = cy * samplesPerLine + cx;
          data[offset] = lineData[index];
          offset += numComponents;
        }
      }
    }
    return data;
  }

  getData(width, height) {
    var scaleX = this.width / width,
      scaleY = this.height / height;

    var component, componentScaleX, componentScaleY;
    var x, y, i;
    var offset = 0;
    var Y, Cb, Cr, K, C, M, Ye, R, G, B;
    var colorTransform;
    var numComponents = this.components.length;
    var dataLength = width * height * numComponents;
    var data = new Uint8Array(dataLength);
    var componentLine;

    // lineData is reused for all components. Assume first component is
    // the biggest
    var lineData = new Uint8Array(
      (this.components[0].blocksPerLine << 3) *
        this.components[0].blocksPerColumn *
        8
    );

    // First construct image data ...
    for (i = 0; i < numComponents; i++) {
      component = this.components[i];
      var blocksPerLine = component.blocksPerLine;
      var blocksPerColumn = component.blocksPerColumn;
      var samplesPerLine = blocksPerLine << 3;

      var j,
        k,
        ll = 0;
      var lineOffset = 0;
      for (var blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
        var scanLine = blockRow << 3;
        for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
          var bufferOffset = getBlockBufferOffset(
            component,
            blockRow,
            blockCol
          );
          var offset = 0,
            sample = blockCol << 3;
          for (j = 0; j < 8; j++) {
            var lineOffset = (scanLine + j) * samplesPerLine;
            for (k = 0; k < 8; k++) {
              lineData[lineOffset + sample + k] =
                component.output[bufferOffset + offset++] *
                component.bitConversion;
            }
          }
        }
      }

      componentScaleX = component.scaleX * scaleX;
      componentScaleY = component.scaleY * scaleY;
      offset = i;

      var cx, cy;
      var index;
      for (y = 0; y < height; y++) {
        for (x = 0; x < width; x++) {
          cy = 0 | (y * componentScaleY);
          cx = 0 | (x * componentScaleX);
          index = cy * samplesPerLine + cx;
          data[offset] = lineData[index];
          offset += numComponents;
        }
      }
    }

    // ... then transform colors, if necessary
    switch (numComponents) {
      case 1:
      case 2:
        break;
      // no color conversion for one or two compoenents

      case 3:
        // The default transform for three components is true
        colorTransform = true;
        // The adobe transform marker overrides any previous setting
        if (this.adobe && this.adobe.transformCode) colorTransform = true;
        else if (typeof this.colorTransform !== 'undefined')
          colorTransform = !!this.colorTransform;

        if (colorTransform) {
          for (i = 0; i < dataLength; i += numComponents) {
            Y = data[i];
            Cb = data[i + 1];
            Cr = data[i + 2];

            R = clampToUint8(Y - 179.456 + 1.402 * Cr);
            G = clampToUint8(Y + 135.459 - 0.344 * Cb - 0.714 * Cr);
            B = clampToUint8(Y - 226.816 + 1.772 * Cb);

            data[i] = R;
            data[i + 1] = G;
            data[i + 2] = B;
          }
        }
        break;
      case 4:
        if (!this.adobe) throw 'Unsupported color mode (4 components)';
        // The default transform for four components is false
        colorTransform = false;
        // The adobe transform marker overrides any previous setting
        if (this.adobe && this.adobe.transformCode) colorTransform = true;
        else if (typeof this.colorTransform !== 'undefined')
          colorTransform = !!this.colorTransform;

        if (colorTransform) {
          for (i = 0; i < dataLength; i += numComponents) {
            Y = data[i];
            Cb = data[i + 1];
            Cr = data[i + 2];

            C = clampToUint8(434.456 - Y - 1.402 * Cr);
            M = clampToUint8(119.541 - Y + 0.344 * Cb + 0.714 * Cr);
            Y = clampToUint8(481.816 - Y - 1.772 * Cb);

            data[i] = C;
            data[i + 1] = M;
            data[i + 2] = Y;
            // K is unchanged
          }
        }
        break;
      default:
        throw 'Unsupported color mode';
    }
    return data;
  }
}

export default JpegImage;
